function bar(){
    var myname = 'Tom'
    let test1 = 100
    if(1){
        let myname = 'Jerry'
        console.log(test,myname); // 1 Jerry
    }
}
function foo(){
    var name = '彭于晏'
    let test = 2
    {
        let test = 3
        bar()
    }
}
var myname = '晟哥'
let test = 1
foo()